Pharmaceutical lactose : a new whey with no waste

The Australian dairy industry produced 3.3 million tonnes of whey in 2002/03, yet converted only half of this into saleable products, with the remainder disposed, risking environmental problems rather than maximising returns (Dairy Australia 2003). Arising from Australia's continuing problems with whey disposal, research was commenced into whey processing with the objective to develop an integrated lactose process that minimised waste, reduced costs and maximised by-product utilisation, while producing a commercially viable and high-value product. The basis of the new process was the use of ion exclusion chromatography to separate and purify lactose, increase yields and reduce the effluent problems usually associated with traditional processes. The chromatographic separation was optimised to maximise yield and throughput, then integrated with the unit operations upstream and downstream to further maximise yield and throughput. Further work was done to evaluate the by-products of each operation, developing procedures for their reuse within the process to yield high-value by-products, including pharmaceutical-grade lactose, purified water, soluble whey minerals and high calcium supplements. The end result is a fully integrated food process that achieves zero discharge by waste minimisation and by maximising the profits from whey.